A longer version of this article was published by the Center for the National Interest and it can be found here.
For decades, a third rail of US nuclear power policy has been reprocessing spent fuel and extracting the plutonium. The country has alternately supported and suspended reprocessing over the past decades, and now the pendulum seems to be swinging back in favor of it as the Trump administration seems intent on sweeping the taboo away. But it needs to think carefully about how that policy transition is achieved and what is gained and lost in the process.
The Policy Is Porous
While the United States has sought to stop reprocessing overseas for security reasons, it has supported its use and experimentation in limited circumstances at home and winked at allies’ activities.
France, Russia, and India continue to operate reprocessing plants, while Japan has a facility that is not operating because of technical and political challenges. China has a plant under construction. Since 1978, the U.S. has provided advance consent to Japan to reprocess spent nuclear fuel of US origin.
Under a Joint Fuel Cycle Study program with South Korea, an offshoot of traditional reprocessing, known as pyroprocessing, has been used in experiments on the separation of irradiated light water reactor fuels. At an August 2025 US-South Korea summit, agreement was reached to further discuss nuclear fuel reprocessing as part of bilateral cooperation.
Domestically, the U.S. is using pyroprocessing to treat spent fuel from the now-closed Experimental Breeder Reactor-II at Idaho National Laboratory. And the Biden administration provided tens of millions for reprocessing technology research, development, and demonstration projects by national laboratories and advanced reactor companies, including TerraPower and Oklo.
Policy Tension and Technology
The nonproliferation imperatives that undergirded U.S. opposition to reprocessing are now facing new challenges as nuclear power has emerged as an important technology in strengthening global energy security, winning the geopolitical battle with China and Russia, and supporting global carbon emission reductions.
Supporting American nuclear competitiveness is a central tenet of the Trump administration’s nuclear executive orders. But it will now have to assess policy priorities that traditionally have not been in conflict but may be in competition now.
Plutonium and Proliferation
Nuclear proliferation and nuclear terrorism concerns have been the dominant factor in assessing the national security danger of reprocessing.
An estimated 560 metric tons of plutonium has been separated, with 140 tons of this amount available for weapons and the remainder in storage ostensibly for civil purposes. American experiments have concluded that “reactor grade” plutonium (less pure than weapons grade) can be weapons usable. The largest stockpiles are held by Russia, the United States, and France.
The IAEA assesses that only 8 kilograms of plutonium are needed for a crude nuclear device. So, U.S. policymakers will have to continue to take seriously the nuclear weapons usability of separated plutonium when considering loosening the reins on reprocessing.
Pyroprocessing Ambiguity
Using the traditional method of aqueous spent fuel reprocessing produces a very pure stream of plutonium suitable for nuclear weapons. Pyroprocessing has been proffered as a less proliferation-prone technology. It uses an electrometallurgical processing technique that leaves the fissile materials adulterated with irradiated nuclear waste products.
The controversy is whether the pyroprocessing technique makes the resulting material more “proliferation resistant” than traditional aqueous reprocessing. The Trump administration seems to have accepted the argument that pyroprocessing is less proliferation prone. However, there is a persuasive counter argument that while it may be marginally more proliferation resistant, nuclear weapons concerns emerge if further processing is done.
Reprocessing Intentions
The goal of engaging in reprocessing is important. The concern has been about the intent of foreign nations. But the renewed interest in reprocessing is being driven by U.S. advanced reactor companies as part of their competitiveness strategy.
These companies acknowledge the importance of preventing nuclear proliferation and support safeguards and security. There has been no statement of interest from them in using plutonium for anything other than reactor fuel. And so far, there’s no intent to build reprocessing plants outside the U.S.
It is too soon to tell if the emerging reactor market will require a competitive boost from reprocessing spent fuel. The plants are expensive, and the reactors are years away from demonstration or deployment. U.S. policymakers will need to identify a clear and compelling competitive advantage before over committing to reprocessing.
Power of American Precedent
The resurrection of spent fuel reprocessing in any form by the U.S. will raise concerns that it will set the wrong precedent and signal the acceptability of the technology to other nations. This argument has limits.
The U.S.’ influence on other nations has been linked to its role as an international nuclear supplier and past market domination deeply declined beginning in the 1980s. It seems unlikely that the Trump administration will prioritize the perceived value of precedent over concrete competitive advantage. But it is an issue worth watching in a volatile international environment where priorities can quickly pivot.
Geopolitics and Economics
The geopolitical competition around expanded nuclear deployment is intensifying. There are clear political and security dangers in allowing Russia and China to dominate the nuclear market of the 21st century. But non-aligned and developing economy nations that seek nuclear energy may not care much about the advantages offered by democratic-nation nuclear suppliers when Russia and China are offering significant financial package advantages.
One of the major omissions of the voluminous Trump nuclear policy executive orders was a plan for financing the nuclear build-out at home and abroad. Devoting government financing to spent fuel reprocessing expansion could limit the funds available to support American nuclear competitiveness, impacting the ability to win essential emerging markets.
Ken Luongo, President, Partnership for Global Security
